MRI tagging and HARP tracking successfully detected reduced end-systolic radial strain and torsional shear in vinculin-deficient mice compared to wild-type littermates.
MRI tagging with HARP tracking is feasible for detecting early alterations in 3D myocardial strain distributions in genetically engineered mouse models of cardiovascular disease.
A model-based method for calculating three-dimensional (3D) cardiac wall strain distributions in the mouse has been developed and tested in a genetically engineered mouse model of dilated cardiomyopathy. Data from MR tagging and harmonic phase (HARP) tracking were used to measure material point displacements, and 3D Lagrangian strains were calculated throughout the entire left ventricle (LV) with a deformable parametric model. A mouse model where cardiomyocytes are specifically made deficient in vinculin (VclKO) were compared to wild-type (WT) littermates. 3D strain analysis revealed differences in LV wall mechanics between WT and VclKO mice at 8 weeks of age when systolic function had just begun to decline. Most notably, end-systolic radial strain and torsional shear were reduced in VclKO hearts which contributed to regional mechanical dysfunction. This study demonstrates the feasibility of using MRI tagging methods to detect alterations in 3D myocardial strain distributions in genetically engineered mouse models of cardiovascular disease.
Chuang et al. (Wed,) conducted a other in Dilated cardiomyopathy. MR tagging and harmonic phase (HARP) tracking vs. Wild-type (WT) littermates was evaluated on 3D Lagrangian strains (end-systolic radial strain and torsional shear). MRI tagging and HARP tracking successfully detected reduced end-systolic radial strain and torsional shear in vinculin-deficient mice compared to wild-type littermates.